This contract is one of a number of awards solicited under a single RFP designed to put in place a number of clinical research facilities that would have the capability of performing Phase 1 and Phase 2 clinical studies in patients infected with HIV (Human Immunodeficiency Virus). These studies are necessary for the NIAID to identify a safe and possibly efficacious treatment regimen for this infection. The studies will provide information, in addition, on the pharmacokinetics of the drugs evaluated and their metabolites. The contractor will be responsible for assessing the patient's response therapy using performance status, drug response, pharmacokinetic assays, and toxicity criteria designated in advance. The contractor will be responsible for performing viral isolation assays from a variety of clinical samples, for evaluating immunologic status prior to, during, and after therapy, and for performing in-depth pharmacokinetic analysis on a subset of patients treated. Clinical status of the patients will be regularly monitored. Data will be submitted by remote entry to a centralized coordinating center. Investigators will meet regularly with the AIDS Drug Selection Committee to discuss current and future studies and resolve technical issues through focused workshops. The contract also includes a Part B which consists of a similar statement of work as Part A but is directed at clinical studies of the opportunistic infectious commonly seen with patients with AIDS.